In a multiple-input multiple-output (Multiple-Input Multiple-Output, MIMO) communications system, data, control signaling, and/or other information may be sent and received between devices in the communications system by using a plurality of sources and/or destinations (for example, corresponding to antennas). In some cases, compared with a single-input single-output communications system, the use of the plurality of sources and/or destinations for each shown transmission related to the MIMO communications system can result in a higher data rate, improved signal quality, and other similar advantages.
An example of the MIMO communications system is a coordinated multipoint transmission (Coordinate Multipoint Transmission, CoMP) system. In the transmission system, a plurality of transmission points (Transmission Point, TP) may coordinate, to exchange information with one or more reception points (Reception Point). When the plurality of transmission points coordinate to transmit data to a reception point, one transmission point may send a user-specific demodulation reference signal (DeModulation Reference Signal, DMRS) to the reception point, and the reception point can estimate a channel based on the demodulation reference signal sent by the transmission point, and then receive data sent by the transmission point and demodulate the data. In the prior art, a time-frequency resource location to which the DMRS sent by the transmission point to the reception point is mapped may overlap with a time-frequency resource location to which data sent by another coordinated transmission point to the reception point is mapped. Consequently, the reception point cannot correctly receive the DMRS, and then the reception point cannot correctly estimate the channel. Consequently, data receiving performance of the reception point is degraded, and system performance is degraded.